Manny Padilla, a teen-age musician living with obsessive-compulsive disorder, faces intense fears and intrusive thoughts. When left unchecked, they can make him feel like he’s living in a different reality from other people. A focal point of his fear is universal: being alone. Beyond creating feelings of anxiety, Manny’s mother, Lori, says, obsessive-compulsive disorder “infiltrates every bit of your life.” Everyone experiences passing moments of worry, but with O.C.D. such thoughts become so invasive that the person experiencing them finds compulsions in order to cope. For Manny, these behaviors have included not plugging in electronic devices, or washing his hair a specific number of times.

In Charles Frank’s documentary “Lost in My Mind,” we meet Manny—who has lived with obsessive-compulsive disorder since the age of nine and is now nineteen—at home in his bedroom, eager to show off his singing and songwriting. We then see him doing activities that spark his anxiety as part of an intensive treatment program using a therapy called Exposure and Response Prevention (E.R.P.) and pausing to register the level of his reaction. He’s a sympathetic character, both because of the difficulty of what he’s struggling with and because of his commitment to making his life better.

The filmmaker Charles Frank also has O.C.D. and went through the same exposure-therapy treatment when he was younger than Manny. The two met when Frank—whose previous documentary subjects include education in prison, football in the Native Red Lake Nation, and New England fishermen—put out a call for an O.C.D. patient to interview. Manny had a personal reason for agreeing to share his story in a film. “Manny discovered that what he was experiencing might be O.C.D. because of a documentary he watched that the Channel 4 did years ago. And his family didn’t know what it was that he was struggling with. But because they saw somebody else that was going through [the same thing], they were able to research it and find treatment options,” Frank told me.

Frank also said that, until recently, he had been less interested in sharing his own experience with O.C.D. “I realized if Manny and the Padilla family are going to be so open about it, then I should, too.” Depictions of O.C.D. often focus on a desire for sterility and order, but, Frank emphasized, not everyone has the same experience. “Any obsessive thought that is paired with a compulsive behavior can be O.C.D., and it can be really, really diverse in the way it manifests,” he said.

One of Manny’s fears is of using electric devices. “Anything electric is hard for me to use. I feel like if I touch it, it’s going to zap me into a different world,” he says in the film. So it’s a watershed moment when Manny offers to pick up his old computer—six months earlier, he had been moving it when he experienced a wave of anxiety so extreme that he threw the machine. Since that incident, Manny has made enough progress, through his exposure therapy, to pick up the computer, turn it on, and begin to use it.

Both Frank and Manny are remarkably honest and empathetic, and the result is a film that reveals the intense work that goes into Manny’s quest to gain control and live in the moment. Beyond the courage required by the exposure therapy itself, Manny reveals the bravery not only to allow a film camera into his home and personal space but also to share his story with an anonymous viewing public. His vulnerability is a kind of generosity, exposing a difficult path in the hope that it will help someone else to find a better one.